Biodegradable Cellulose Nanofibril Films with Active Functionality for Food Packaging Applications

Cellulose nanofibrils (CNFs) can form hydrogen bondswith eachother, creating strong, flexible films with good oxygen barrier properties.However, they are vulnerable to the water-induced loss of film integrity.Targeted modification with phenolic acids can improve their hydrophobicity,provide active functionality for food packaging applications, andreduce their susceptibility to moisture. In this study, precastedCNF films were esterified with cinnamic acid and its derivatives usingtwo different esterification methods. The modified films were investigatedfor the evidence of esterification, changes in hydrophobicity, mechanicalproperties, and capacity to increase the shelf life of model foods.Modification techniques utilized resulted in esterification of CNFfilms; with films acquiring antioxidant activity (80 & PLUSMN; 9% DPPHradical scavenging activity) and significantly increased hydrophobicity(101 & PLUSMN; 4 & DEG; water contact angle) as compared to control CNFfilms. Overall, esterification of CNF films with cinnamic acid orits derivatives significantly reduced the films' susceptibilityto water while also providing important added functionality.